We’re worried he’s going to overstress himself. This is a serious business, a presidential run. You have to have an inner fire. Sen. Bernie Sanders may be 77, but he has the berserk energy of Woody Woodpecker (whose cartoons he likely saw during their original runs at the Midwood Theater on Avenue J).

De Blasio is 58 years old and has all the vim of a guy wearing a Grateful Dead T-shirt during the sixth hour of a Phish concert.

Hizzoner’s solipsistic delusion either about winning the nomination or having a significant effect on the national debate has an obvious root. All politicians have a nest of courtiers who survive and thrive off their proximity to the person in power — and who take it as part of their terms of employ to feed their sire’s ego.

I once met with the governor of a Rust Belt state who was, at the time, literally the most unpopular politician in America. This was a guy who couldn’t have gotten elected dog catcher by that point; a year later, he lost his re-election bid by 10 points, having won by 10 points four years earlier.

Midway through the meeting, as he was talking about some boring national issue, one of his sycophants cut in and said: “Careful, Governor, you don’t want to telegraph anything about your upcoming plans.” Whereupon the governor said we needed to go off the record and, looking me straight in the eye, said in a low voice that he and his aides were seriously considering a run for the presidency.

That governor didn’t run. And in all fairness, de Blasio is the mayor of a city he won in two successive landslides (albeit with turnout smaller than the number of people who saw “The Oogieloves in the Big Balloon Adventure,” the worst-performing movie in history). He might as well run. Everybody else is.

The problem is that by this point in 2019, entering the presidential race without much money or support is a little like getting a last-minute e-vite to a birthday party to which everyone you know — including people you are sure are dumber and less attractive and have less right to attend than you — has already received a hand-delivered, calligraphed invitation on 140-pound stationery with raised lettering.

(Yes, I know, Bill Clinton didn’t get into the 1992 race until October 1991. That was 28 years ago, people! That was seven presidential elections back! Live in the now!)

In his announcement video, during which he bizarrely cites his policy successes while looking about for something invisible that’s apparently floating three feet above his head and to the right, de Blasio says he’s running for “working families.” That’s nice. Truth to tell, if he gets any purchase at all, he will be running to get Joe Biden the nomination.

How so? Every poll at the moment has Biden leading by dazzling margins nationally (20 points up in Morning Consult, 25 in CNN, 30 in Harvard/Harris) and in the early primary states (by 18 in New Hampshire in Monmouth, by 31 in South Carolina in the Post and Courier and in Iowa by 4 in the RealClearPolitics average). The more candidates there are fighting for the rest, the better chance Biden has simply to front-run his way to the nomination.

The better de Blasio does in selling his progressive message, the more he will threaten Sanders or Sen. Liz Warren or others in the race running sharply to the left. If the intersectional socialist ideological tendency doesn’t cohere around a single candidate, and instead squabbles over who’s more pure and who’s more identitarian, Biden’s essential message will be made flesh.

De Blasio and others will make the case for Biden that he’s the only person with standing who can take on President Trump and hit the president in his own base, white working class. And then, if Biden becomes president, he can reward de Blasio for his help by making him ambassador to … Jamaica.